For 40 years, Michael Forbes has lived a quiet life netting salmon every summer like his father and grandfather before him. His rambling old farm nestles behind a rampart of vast sand dunes which protect his rusting tractors and ramshackle sheds from the winds that whip in from the North Sea.

But those dunes are coveted by the billionaire property developer Donald Trump, as the centrepiece of his plans to create the "world's greatest golf course" - a £500m project to plant an eight- storey five-star hotel, two championship golf courses and 950 timeshare holiday flats on the coast of Aberdeenshire.

In the middle of Mr Trump's dream - just below the proposed hotel on Trump Boulevard, the elite golf academy and a short swing from the greens - sits Mr Forbes' weather-stained house, his mother's neatly kept mobile home and their roaming tribes of geese, cats and hens.

And Mr Trump is far from pleased. During a press conference called to bolster his attempt to build the Trump International resort, he singled out Mr Forbes for attack, bluntly describing the fisherman's property as a "disgrace" which damaged his visionary scheme for an award-winning resort the world would envy.

Without naming his new neighbour, Mr Trump told the assembled TV crews and reporters: "The sad thing is that a gentleman who has a small area near the site ... the area is in total disrepair. Take a look at how badly maintained the piece of property is: it's disgusting. Rusty tractors, rusty oil cans - I actually asked him: 'Are you doing this on purpose to try and make it look bad, so I have to pay some more money?' "

Mr Forbes was portrayed as "an angel", he added. "But he's not, he's a tough guy, a tough, smart guy. You see the environment when you've rusting oil cans leaking oil down in the soil. I think it's a shame."

Mr Forbes, a stocky, grey-haired and ruddy-faced 55-year-old, is unrepentant. He is in no doubt that Mr Trump is unhappy: he has refused several offers from the billionaire's lawyers to buy his 23 acres of land, offers that have slowly edged up to £375,000.

"To me, you can't put a price on it. I just won't sell, and he knows that," Mr Forbes said yesterday. "All my family came from here. My grandfather fished down here, my father fished down here and my uncles fished down here, and I'm last in line and will see it out. I'm right in the middle, you see. I wasn't against the golf course from the start. I was helping him out and repairing their roads and things, and then they just went mental because I wouldn't sell. They said they would make my life a misery, which they are ... He can go back to his own country and bother someone else."

On his lawn flutters a blue and white saltire flag. One of Mr Forbes' barns bears the graffito in dark red capital letters "no golf course", a slogan he says was painted without his permission one night. And just down the single-track, unsurfaced road sits the target of Mr Trump's attack: a large yard home to a fleet of ancient tractors and farm machinery.

Mr Forbes says this is no junkyard. The tractors are used to haul his heavy nets and their frames in from the sea, while the oil cans are makeshift braziers for burning rubbish. "If I had the money he has, this place would be like a palace as well. "

His mother, Molly, 83, is equally implacable. "I object to his skyscraper hotel. It will be an ugly monster," she said. "I came here to live in peace."

Mr Forbes is already in a legal dispute with the Trump organisation whose lawyers, he says, are trying to prevent him from crossing the billionaire's dunes to the sea to set his salmon nets. The fisherman claims this dispute is part of a campaign to unsettle him.

Ever since he refused to sell his home, 13 miles north of Aberdeen, Mr Forbes claims he has had a series of visits: environmental health officers and animal cruelty inspectors have arrived to check on the animals, and the police have asked him about his alleged possession of an unlicensed shotgun - a weapon he does not own. He has also had lawyers' letters accusing him of damaging Mr Trump's property, which he denies. These visits could be a coincidence, he adds, but he believes the pressure to sell will intensify.

Last night, George Sorial, Trump's managing director for international development, denied that Mr Forbes had been harassed and said he had been threatening and aggressive.

The Trump organisation had initially tried to negotiate with Mr Forbes, Mr Sorial said, including offering him a job at the resort and to relocate him and his mother. But he claimed Mr Forbes was trying to force Mr Trump into paying a higher price for the plot. "He has become very greedy. He wants huge, outrageous numbers."